1. Field of the Invention
The present application relates to a locator system for locating a person, animal or mobile structure whose whereabouts is sought, either because a person, animal or structure is lost, abducted or for any other reason that the location is sought.
2. Description of the Prior Art
Numerous systems relating to containing, communicating with and locating children, older persons and animals are well known. One type of system includes a loop of wire for which an alarm is actuated if a person or animal wearing an appropriate device goes near or crosses the loop. See U.S. Pat. No. 3,753,421 (Peck, 1971), U.S. Pat. No. 4,745,882 (Yarnall, Sr., et al., 1988) and U.S. Pat. No. 6,650,241 (Osborne et al., 2003). Other security, locating and monitoring systems are disclosed in U.S. Pat. No. 3,980,051 (Fury, 1976), U.S. Pat. No. 5,714,932 (Castellon et al., 1998), and U.S. Pat. No. 5,812,056 (Law, 1998). There are also a number a devices around involving collars with electrical systems that are used primarily for training pets. Such type of collars are disclosed in U.S. Pat. No. 4,202,293 (Gonda et al., 1978), U.S. Pat. No. 4,335,682 (Gonda et al., 1982), U.S. Pat. No. 4,794,402 (Gonda et al., 1988) and U.S. Pat. No. 5,161,485 (McDade, 1992). U.S. Pat. No. 3,980,051 (Fury, 1976) is directed to an animal training system wherein a pulse transmitter and receiver are included in the first housing in the vicinity of a dog or pet master disposed in a housing worn by the pet for receiving a pulse sound from the transmitter which repeats the pulse and transmits it back to the receiver in the first housing; if the pet moves beyond a certain distance and no response is received, a dog whistle is actuated to signal the animal to return. Various monitoring and locating systems are known, such as those disclosed in U.S. Pat. No. 5,714,932 (Castellon et al., 1998) and U.S. Pat. No. 5,812,056 (Law, 1998).
Cellular telephones are extremely well known and used throughout the world. Cellular telephones are electronic transceivers having a display, a keypad, a microphone speaker and related electronics. The transceiver uses a standard protocol which is often a code division multiplex access (CDMA) or a Global System for Mobile communication (GSM). GSM communications are the most popular standard for mobile telephones in the world. They are used by 1.5 million people in over 200 countries and territories. The signalling and speech channels of GSM are digital. About 70% of the world's market in mobile telephone systems uses the GSM protocol. GSM is a cellular network to which connection is made by cellular phones looking for cells in their vicinity. Most GSM networks operate at 900 MHz or 1800 MHz bands. In some parts of the United States and Canada, they operate at 850 MHz or 1900 MHz because the other two frequency bands had already been allocated.
Global positioning systems (GPS) are well known satellite navigation systems. GPS is funded by and controlled by the U.S. Department of Defense. GPS provides specially coded satellite signals that can be processed in a GPS receiver, enabling the receiver to compute position in longitude, in latitude and altitude There are many satellites that orbit the earth in respective fixed orbits. GPS navigation is widely used, and GPS devices are available in automobiles, handheld devices and the like. Space vehicles (SV) transmit to microwave carrier signals carrying the navigation message and the standard positioning service (SPS) code signals. Baseband processors are also well known for, in effect, actuating a GPS unit for, in effect, requesting the GPS unit to update itself.